Elevator control system



Oct. 16,1928. 4 1,687,654

' E. M. BOUTON ELEVATOR CONTROL SYSTEM Filed Feb. 16, 1922 WITNESSES:INVENTOR I [d f7. 5 7 n 1% ig! ou 0 ATTORNEY 1 ing sheave and the cablesfor operating th Patented 0a. 16, 1928.

v UNITED STATES PATENT OFFICE.

EDGAR; m. nou'roN, or EAST PITTSBURGH, PENNSYLVANIA, Assronon 'roWESTING- nousn nnno'rnrc a MANUFACTURING COMPANY, A CORPORATION orPENNSYL- VANIA.

ELEVATOR CONTROL SYSTEM.

Application filed February 16, 1922. Serial No. 586,872.

' may be desired.

Another object of my invention is to provide a system wherein anelevator car or other device may be controlled with extreme accuracywithin predetermined limits of motion.

Many systems of control have been employed in connection with elevatorsand hoists in an endeavor to secure accurate stops or landings,independently of the skill-of the operator. Such systems are, as a rule,rather complicated and, in some instances, not sufiiciently effective orsatisfactory.

My invention is particularly adapted for use in connection withhigh-speed elevator machines of the traction type. which are generallyunderstood as comprising a motoroperated driving-sheave and a secondarysheave. The hoisting cables are wrapped about the sheaves in such mannerthat effective traction is established between the drivcar. In additionto the standard elevator machine and the usual control apparatus, Iprovide an auxiiiary hoisting machine for connection, means oi anelectro-magnetic cintch. to the secondary sheaves. My system of controlis arranged for selectiveiy operatic the car by one or the other ofthese hoisting defines. The control of the main Easter is cied by meansof the usual type ereas auxiliary motor is or pair of reversing that arerecanted en the car acso i y came in elevator hatchway. ese areefiective to control the operathe e'ievator ear within predeterminedtravel, with respect to each floor level.

' lhe single figure of the drawing is a diagrammatic representation ofcircuits and apparatus embodying my invention.

The main hoisting motor, having an armature 1 and a field-magnet winding2, is operatively connected to line conductors 3 and 4 through reversingswitches 5 and 6. The

main driving-sheave 7 is mounted on the armature shaft. The usual formof electromagnetic brake 8 is provided.

A starting resistor 9 may be controlled by i an accelerating switch 11in any well-known manner. A controlling switch, having an operatinglever 12, is located within, and normally controls the operation of, thecar 13. Auxiliary reversing switches 14 and 15 cooperate with astationary contact mem ing 29 and an electromagnetic clutch 31, to

drive the secondary sheave 32. Either the main or the auxiliary motormay be employed for operating the elevator car-13;

In one instance, the sheave i operates as the driving member, that is,while the clutch 31 is released, whereas, when the sheave 32 is operatedas the driving member, the clutch 31 is effective to transmit power fromarmature 17. In the latter case, the elecpositions by means of springs19" tromagnetic brake 8 is released and the main armature l is drivenidly, together withzthe by means or the hoisting cables that at themovements the elevator car.

"nxiliary reiay controls th'e'electroinaily closed reiay andacentrifugal governor 35, for controlim the electromagnetic brake 8. Thecentriaug algovernorfifi is operativeiy connected, in any convenientmanner, to function in accordance with the" speed of the elevator car13." the operation of my system will'be more clearly understood fromthejfo'llowmg description. In normal operation, the elevator etic brake28 ice-operates with a car 13 is governed, in a well knownmanner,

by the operating lever 12 of the car switch which controls the directionof rotation of the main armature 1 by means of reversing switches 5 and6. This much of the operation is so well understood and so old in theart, that further. detailed description is considered unnecessary.. V Itmay be assumed, however, that the car 13 is Operating at normal speedand that the operator returns the lever 12 to its ino rative orillustrated position to effect a anding, substantiallylevel with thefloor 23. If the car is moving upward and tends to stop below the levelof the floor 23, the cam 22 ac* tuates switch member 16 to continue theu ward movement of the car, by means of t e auxilia hoisting mechanismand independently o the operator. .It may be assumed that thegovernor-switch members 36 and 37 respectively occupy the positionsillustrated in thedrawing and which correspondto a ve "slow operatingseed. v

, auxiliary circuit for effecting u ward movement of the car 13 extendsfrom t e line conductor 3 through conductor 38, the operat-' ing coil ofrelay 33, the operating coil of reversing switch 24, conductor 39,contact members 14 and 16, governor switch 37, carswitch members 41 and42 and conductor 43 to-line conductor 4. The relay 33 closes'toestablish a'circuit for the operatin coil of conductor 3- throughconductors 38 and 44, relay 33 and the operatin coil of brake 28 p toline conductor 4, thereby effecting a release of the brake 28.Electromagnetic brake 8 is also'released by the energization of anauxiliaryoperatin coil 45, 'connectedin series relation with thearmature 17, the circuit for which extends from line conductor 3 throu hresistor 26, switch 24,0 crating coil 45, re ays 33 and 34, armature 1724 to line conductor 4. Power is su plied to the auxiliary armature 17by the clbsure of up reversing-switch 24,-whereby, upon re lease ofbrake magnets 8 and 28, power is ap plied through the'clutch '31 fordriving the sheaves 32 and 7. a

It is obvious that the auxiliary coil 45, which is in series relationwitharmature 17 is energized in proportion to the elevator 10a and thecurrent traversing the armature 17. With-light load, for example, themain brake 8 is not fully released and. mposes additional load on theauxiliary motor. Consequently, the auxiliary motor always operates underload and at a uniform speed.

It is also'obviousthat a shunt coil ma be emplo ed, inlieuof series coil45, in w ich case t e main brake .8 will be fully released irrespectiveof load conditions the coil would be connected to' line conductors 3 and4, through relays 33 and 34.- v

When the car13 has attained a level with the floor 23,'s'witchmember 14returns to its normal or illustrated sition to interrupt the operatingcircuit th i electromagneticbrake 28, extending rom line and switchgagement until the car is substantially level rough contact mem-" ber16, aspreviously traced. The switch 24 opens to interrupt the operatingcircuit for armature 17, and rela 33 opens to effect the application ofthebra es 8- and 28.

A movable clutch member 46, during the operation just described, ismaintained in engagement' with stationary clutch member 47 by means of acompression spring 48. How- 'ever, during normal operation of theelevator,

the clutch members 46 and 47 are disengaged 76 by means of an operatingcoil 49, which is ener ized simultaneously with the main operating coil50 of the brake 8. As illustrated, these coilsare connected in seriesrelation.

' When the car 13 is operating above a predetermined speed, governorswitch 36 is closed and a circuit is established for an auxiliary coil51, whichoperates inde endently of coil '49, for maintaining the clutc31 inopbe ener 'zed through relay 34. The auxiliary clutch-' olding'coil51 also is deenergized by the opening of governor switch 36, and 'theclutch 31 does not become effective as a driving member until the speedof the elevator car has been reduced to a proper value, corresponding tothe operating speed of the auxiliary motor 20. In other words, therelative speeds of armature 17 and sheave 32 are controlled by means ofthe governor 35 prior to the engagement of clutch members 46 and 47 Itis manifestly impractical to drive the auxiliary motor at a speedcorresponding to the highest operating s eed of the elevator, for whichreason the c utch mechanism is provided.

Referring again to the sloweed operation, it is evident that downwamovement of the car 13 is effected or continued upon the enga ement ofcontact members 15 and 16, as when the car tends to stop above the levelof .the floor 23. In this case, the cam 22 maintains switch members 15and 16 in enwith the floor 23, corresponding to its illustratedposition. The downward movement ofthe car is efl'ect'ed by the closureof reversing switch 25 and relay 33, a circuit for the operating coilsof which extends from line 125 conductor 3 through conductor 38,operating coil of relay 33, operating coil of switch 25, switch contactmembers 15 and 16, governorswitch 37, carswitch members 41 and 42 andconductor 43 to line conductor 4. All other 180 operating circuits areas previously described in connection with the upward movement of theelevator. i

It will be recognized that my system of control may be readily appliedto any standard elevator equipment and lends itself to such applicationsin a very practicalvmanner. Assuming that the elevator is designed for anormal operating speed of say five hundred feet per minute, theauxiliary machine for driving the secondary sheave may be very small, toeffect operation of the car at say 7 twenty-five feet per minute. Theauxiliary machine'is not subjected to heavy strains, since these areborne by the main hoisting machine and the secondary sheave. The torquenecessary for operating the car by means of the secondary sheave at thereduced speed is low, compared to that required of the main motor tooperate the car at its normal speed. Also, in stopping, the

main brake is applied and assumes the major portion of the worknecessary to'bring the elevator to rest.

I claim as my invention 1. The combination with an elevator and a mainhoisting motor therefor, of leveling .means for sald elevator comprlslngan auxlllary motor and braking means for variably loading said auxiliarymotor to secure uniform leveling operations of said elevator.

2. The combination with a main motor for operating an elevator ear and abrake therefor, of a coil independent of said motor

